SIMPLE; NOT BIG, but simple is the SZ-1, a self-contained, grey boxed, real and step time sequencer from Casio.

It flitted into Britain just in time for the music fair, and could be seen driving a couple of CZ-101s on the Casio stand. Hence, you will have guessed, it's a MIDI device, and is priced to match the 101's end of the market.

By the above phrase 'not big' we refer not to the plastic 12½in x 8½in x 2½in case, which offers more than generous accommodation for the 32 buttons and LCD display, but to the memory size, which reflects the budget price — 1800 events real time, 3600 step time. Enough for a song, certainly, but not into the multi-synthed arrangements of, say, the Yamaha QX7 £499, for example.

Like the QX7, however, the SZ-1 will remember touch data in its sequences, providing, of course, you've got a velocity sensitive synth to operate it.

In behavioural terms (good Desmond Morris turn of phrase) it responds much like the on-board sequencer for the Casio CZ-5000 synth, but with four, polyphonic sequences (or "tracks") played individually or collectively from the internal clock instead of eight. The controls are laid out to resemble a tape recorder with rewind and fast forward buttons to take you to sections that need extending, or return to bits that should be corrected.

Press the 'real time record' button, and at the same time, the switch for the track you want to fill and the LED above it will begin to flash. Punch 'record', the metronome (which can be turned off) gives a four beat count, and you're in.

If you foul up, reset the sequence to zero and this time select real time/track, then the play button. You'll hear your first recording, and when the cock-up appears, plonk out the correct notes on the connected keyboard (best to start a couple early) and the SZ will immediately switch to drop-in record mode. If the mistakes are at the end, fast forward up to that point to save time. If you're really slick, you can hit rewind as you're doing the original recording to nip back, get it right the second (fifteenth?) time, and soldier on.

For successive sequences, select the backing track you want to hear (which might contain your earlier made chords or bass line) then punch real time, plus the tab for the new track you want to record on, and off you go. You hear your first tinklings, and can play along.

The SZ-1 gives no warning when it's approaching the limit of its memory (it just flashes an "end" message). Memory is doled out to the tracks on a first come first serve basis. So before you embark on anything vital press the 'manual time' button to produce an LCD readout of the number of steps so far used up. Said display also reveals the tempo (min 40, max 256, altered by two incrementing buttons), the MIDI channel number (each track can have a separate assignment), and the note value you're about to insert on the manual data bank, to which we now pass.

Arranged as a square of nine buttons in the bottom left hand corner, plus a tenth for 'rest', this is where you do the step time bit.

Press the desired track and this time the manual record tab, then hit record, and begin entering the data. Choose the pitch by pressing the appropriate note on the keyboard and select the duration using one of the nine SZ buttons. They are strangely ordered as crotchet, minim, semibreve, quaver, semi quaver, demi-semi-quaver, plus dotted time, three in the time of two, and tie, the last three of which can be appended to any of the pre-set note values. Hit the enter button, and you're on to writing the next note.

There seems no way of entering touch info in this mode, but you can copy bars to save time (and memory space) and carry out basic inserts and deletes. Really elegant shuffling and shifting of material is ruled out by not having an alpha numeric way of logging the bars and calling them up; 'copy bars 35 to 38 in locations 46 to 49', for example. But as we said at the start, it's a straightforward device, for those of us who feel more at home with the stop/go buttons of a tape recorder than the bit-consciousness of individual notes, which, according to latest bio-feedback empathy research, scream when you pick them.

A repeat button will loop riffs, but you have to be careful, as ever, to end your recording in beat with the metronome, or your spare bit of silence will be looped as well. (There's a stop footswitch to save you diving for the stop button, but one way I found of getting accurate endings was to go back over the piece, drop-in record the last note again, then punch stop. Not so many fingers to worry about.)

Five D size batteries or a 7.5V DC adaptor keep it powered up (so your sequences stay pickled when the SZ's turned off), and the back panel gives you one MIDI in, two MIDI outs, plus a slot for a Casio RAM cartridge dump (cassette as well, if you prefer). Sliders at the rear will swap the SZ to accept an external MIDI clock, or disable the touch sensitive info (saves some memory).

So then, easy to use, works fast (I played my swiftest notes and all survived without being nipped short by a miserly auto correct) and has a few useful facilities (remembers voice changes in mid sequence, for example). One small complaint. The metronome comes from a tiny speaker on the front panel, but not over the output, so you won't be able to hear it if you're recording on headphones. Could get round it by putting your own metronome beat on a spare track, but that seems a mite long winded.

Neat, cheap, to the point.

CASIO SZ-1 sequencer: £295

CONTACT: Casio UK, (Contact Details).